There is no code pertaining to the scenario.
Your furnace humidifier may be leaking due to a clogged drain line, a faulty water supply valve, or a damaged water panel. To fix it, you can try cleaning the drain line, replacing the water supply valve, or installing a new water panel. If the issue persists, it's best to contact a professional HVAC technician for further assistance.
It will be close to the inside wall where the water supply passes into the house from the line going towards the water meret.
Adding a 220V line to a 150 amp panel is feasible, but you must ensure the panel can accommodate additional amperage. Consult an electrician to confirm if the panel has available space and if it meets the necessary electrical code requirements for the new line.
If you don't know that, should you really be doing this potentially dangerous job.
Single line diagram of mv panel
To turn off the fridge water line, locate the shut-off valve usually found behind the fridge or under the sink. Turn the valve clockwise to close it and stop the water flow to the fridge.
Your main concern in installing anything near a water line is to avoid accidentally driving a nail or screw into the pipe, causing a leak. Therefore it is prudent to allow a separation of at least a few inches. Other than that, there is no reason why a light fixture cannot be close to a water line. The wires are insulated, so they are not going to short circuit as a result of the metal pipe.
Only if you leave the burners or elements on. -If water stops, close gas line or switch off breaker for tank.
"What's My Line?"
Yes install it on the cold water line as close to the heater as possible.
To shut off the water to the water heater, locate the shut-off valve on the cold water supply line leading to the heater. Turn the valve clockwise to close it and stop the flow of water to the heater.
A trap primer line is typically connected to the domestic cold water line, not the DWV system. Its purpose is to prevent evaporation of water in floor drains or traps by periodically supplying small amounts of water. In some cases, local plumbing codes may dictate specific requirements for trap primers.